Chemical testing apparatus



Dec. 10, 1968 J. M. RAIT CHEMICAL TESTING APPARATUS 4 Sheets-Sheet 1Original iled June 11, 1962 INVENTOR- Js'epzz' 77]. Ha?

ATTORNEYS.

Dec. 10, 1968 J. M. RAIT CHEMICAL TESTING APPARATUS 4 Sheets-Sheet 2Original Filed June 11, 1962 mm 9 wk & & Q

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Dec. 10, 1968 J. M. RAIT 3,415,627

CHEMICAL TESTING APPARATUS Original Filed June 11, 1962 4 Sheets-Sheet 5INVENTOR. @Se h 7721 ATTORNEYS.

Dec. 10, 1968 J. M. RAIT 3,415,627

CHEMICAL TESTING APPARATUS Original iled June 11, 1962 4 Sheets-Sheet 4COLORIMETER INVENTOR. Jbsepfi 77?. Faz'f g3 BY I I ATTORNEYS UnitedStates Patent 3,415,627 CHEMICAL TESTING APPARATUS Joseph M. Rait,Snyder, N.Y.

(95 Huxley Drive, Buffalo, N.Y. 14226) Continuation of application Ser.No. 201,677, June 11, 1962. This application Mar. 29, 1966, Ser. No.544,648 15 Claims. (Cl. 23--253) This application is a continuation ofmy pending application Ser. No. 201,677, filed June 11, 1962, forChemical Testing Apparatus and Method, now abandoned.

This invention relates to a new and useful method of and apparatus forprocessing and analyzing liquids. While by no means limited thereto, myinvention is particularly useful in the field of blood chemistry.

Heretofore, many body fluid testing procedures could be performed onlyby skilled technicians, capable of carrying out the various treatmentand testing steps required. As a result, such tests usually have beenconducted at clinics or in laboratories, and not in the offices of thedoctor who takes the sample but must send it out to be tested.

A primary object of my invention is to provide a testing apparatus forblood and other body fluids which can be operated by relativelyunskilled personnel, and which will automatically perform variouschemical analyses on blood and other fluids.

That this object is accomplished with the apparatus of my invention isevidenced by the fact that the operator merely places a liner into areceptacle, deposits a sample of the fluid to be tested in the liner,and presses control buttons denoting the tests to be performed. Theapparatus auomatically prepares final standard and sample solutions, andthe operator merely inserts them in a colorimeter from which a directreading can be taken.

In testing procedures where the sample is compared with a standard, aproblem arises, because the processed sample will vary 'with variationsin temperature, line voltage, reagents, and other factors involved inthe preparation of the sample solution. Therefore, the same sample mightvary widely with respect to a given standard solution.

Therefore, it is another object of my invention to pro vide a method andapparatus in which a standard solution is freshly prepared for eachtest, and for each sample under test.

Still another object of my invention is to accomplish the foregoing inan apparatus which, while relatively simple to operate, is durable anddependable, can be constructed and operated at a cost making itpractical for use in relatively small offices, and will consistentlyprovide a degree of accuracy equaling and often exceeding that which isobtained utilizing routine laboratory procedures.

The method of my invention is characterized in one aspect thereof by thesteps of processing a sample of the fluid under test to produce a samplesolution, and substantially simultaneously processing a standard insubstantially the same manner as the sample, thereby producing a freshstandard solution under substantially the same conditions as the samplesolution, whereby variations incident to processing will affect bothsolutions.

The apparatus of my invention is characterized in 'one aspect thereof bythe provision of sample supply means, standard supply means, processingmeans common to the standard and sample supply means and operable toprepare standard and sample solutions for comparison testing, and meansoperable to place first the standard supply means and then the samplesupply means in communication with the processing means, whereby astandard solution is procesed before the sample solution.

In another aspect thereof, the apparatus of my invention ischaracterized by the provision of sample supply means standard supplymeans, processing means associated with the supply means for preparingstandard and sample 3,415,627 Patented Dec. 10, 1968 lCC solutions forcomparison testing, and .means causing the processing means to prepare afresh standard solution for each sample solution.

The apparatus of my invention is further characterized in still anotheraspect thereof by the provision of extractor means including areceptacle for a sample to be tested, the receptacle having an axisabout which it is rotated, with conduit means adapted for communicationwith processing means .and having an intake end extending along thereceptacle axis and into the receptacle while the same is being rotated.

The apparatus of my invention also is characterized, in other aspectsthereof, by the provision of disposable liners for the sample extractor,a disposable hypodermic having means automatically operable to indicatewhen a predetermined amount of fluid to be tested has been withdrawn andejected, and disposable cuvettes eliminating any necessity for cleaningthereof.

The foregoing and other objects, advantages and charactering features ofthe method and apparatus of my invention will become .clearly apparentfrom the ensuing detailed description of one, presently contemplatedillustrative embodiment thereof, taken in conjunction with theaccompanying drawings illustrating the same wherein like referencenumerals denote like parts throughout the various views and wherein:

FIG. 1 is a fragmentary, isometric perspective view of the cabinethousing the apparatus of my invention, with the top cover open to exposethe extractor bowls and control console;

FIGS 2, 2A and 3 are transverse sectional views of three types ofdisposable, sample receiving liners for the extractor bowls;

FIGS. 4 and 5 are side elevational views of disposable color codedcuvettes into which these standard and sample solutions are deliveredafter processing;

FIGS. 6 and 7 are intended to be placed side by side, and togethercomprise a schematic layout of an apparatus of my invention;

FIG. 8 is a fragmentary, detail view taken about on line 8-8 of FIG. 6;

FIG. 9 is a wiring diagram of the control circuits of my invention;

FIG. 10 is a view, partly in side elevation and partly in longitudinalsection, of a hypodermic of my invention; and

FIG. 11 is a transverse sectional view thereof, taken about on line 1111of FIG. 10.

Referring now in detail to the accompanying drawings, it will be seenthat the apparatus of my invention includes an enclosing housing,generally denoted 1, having a recessed top wall containing a pair ofextractor bowls 2 and 3. Bowls 2 and 3 are adapted to receiveindividual, disposable liners 4 and 5, respectively, and are providedwith suitable means, not shown, for releasably retaining liners 4 and 5therein. The liners are stacked in storage dispensers, of known type,which present the uppermost liner in each stack thereof for removal.

A control console, generally designated 1A, and generally under cover 8'also is positioned in the top wall, closely adjacent the extractor bowlsand liner dispensers, and includes a number of normally open, pushbuttonswitches PBl-PBS for selecting the different tests to be performed. Amaster switch 6 is provided, to turn on the apparatus, and an interlockswitch 7 is provided to insure that actual processing does not beginuntil the hinged cover 8 is lowered to enclose the extractor bowlportion of the apparatus. A separate hinged cover 8 is provided for thecontrol console. Cover 8 carries a pair of intake conduits, forwithdrawing fluids from liners 4 and 5 in bowls 2 and 3, respectively.

The liners 4 and 5 are disposable, being made of an inexpensive plasticor other suitable material. In the illustrated embodiments, they have agenerally circular outline with a dished bottom, although the particularconfigurations can be varied. Liner 4 has an opening through its topwall, for injecting the test sample and for receiving a conduit 12.Liner 5 has a similar opening which is closed by a cover 11 because ofthe deproteinizing reagent 12 provided in the liner 5. Cover 11 isremoved to inject the test sample into liner 5, whereupon the reagent12' will immediately start to react with the sample, and to receive thewithdrawal conduit 13.

Liner 5 also is provided with mixing vanes. In the illustratedembodiment, these take the form of three hollow, internal ribs 5, formedintegrally with the liner and equally spaced about the axis thereof.

Liner 4 is provided with a trap comprising an annular wall 97,concentric with the side Wall, extending upwardly from the bottom wall.Wall 97 serves to trap the heavier constituents, once they have beenseparated.

FIG. 2A shows still another disposable liner 4', of frustro-conical wallform, wherein the blood cells are caused to move outwardly anddownwardly, settling on the bottom as indicated at 95. The plasma 96remains on top, to be withdrawn by conduit 13 which extends into theplasma 96, but stops short of the layer 95. Liner 4' can be providedwith an adaptor, not shown, making it interchangeable with liner 4.

In use, switch 6 is closed, to start up the apparatus, and a light 9indicates when the heating element is ready. The operator lifts a liner4 and a liner 5 out of their respective delivery mechanisms, and placesthem in the appropriate extractor bowls 2 and 3.

When the liners are in their respective extractor bowls, and the samplehas been injected into each liner, cover 8 is closed. This closes switch7, causing the apparatus to start processing and automatically positionsthe intake ends of conduits 12 and 13 in the liners 4 and 5,respectively.

The apparatus automatically processes separate sample and standardsolutions, for each test to be performed, by means to be described. Whenthe preparation is completed, a buzzer 14 (FIG. 9) is energized tosignal the operator that the various sample and standard solutions areready.

The standard solutions are dispensed by the apparatus into disposablecuvettes 1-6 (FIG. 4), and the test or sample solutions are dispensedinto similar disposable cuvettes 17 (FIG. 5). The cuvettes 16 and 17 arecarried in a holder 18, like a test tube rack, which is positioned in awell 19 in the front of cabinet 1 for receiving the solutions. When thesolutions are ready, the operator lifts the entire rack of cuvettes outof well 19 and places it in a well 20 in the top wall console portion,for ease of access. A cuvette 16, containing a standard solution, isinserted in a test well 21 and the colorimeter, generally indicated at22 and provided with a number of control knobs 23, is referenced to thatstandard. Then a cuvette 17, containing a corresponding sample solution,is inserted in well 21 and the colorimeter reading is referred to theappropriate color coded scale which directly indicates the test result.

The illustrated apparatus will perform five different tests, and isarranged to prepare the five standard solutions simultaneously, followedimmediately by simultaneous preparation of five sample solutions. Toavoid confusion, and assist the operator, the various tests aredistinguished by means of color coding. Thus each pushbutton PB1PB5 isof a different color, shown as blue, green, red brown and gray in theillustrated embodiment, although other colors obviously can be used.Cuvettes 16 and 17 are provided with color bands 24, which are coloredto correspond to the code colors of the various tests, and one set ofcuvettes, in this instance the standard cuvettes 16 have an additionalband or mark 25 to distinguish them from the other set of cuvettes. Thecolorimeter dial from which the readings for the various tests aretaken, is correspondingly color coded, as indicated at 26. The number oftests which can be performed by the apparatus of my invention, and theparticular tests which are performed, can be varied as desired.

Turning now to FIGS. 6, 7 and 8, it Will be seen that extractor bowls 2and 3 are arranged to be spun or rotated about their respective axis bymotors 27 and 28, respectively. The speed of rotation is such as toproduce blood plasma within liner 4 or 4' and a deproteinized filtratein liner 5. In this manner, a true filtrate is provided, and not just asmall percentage sampling. I prefer that the standard solution beprepared first, while the samples are being extracted, and that theprocessing lines and apparatus initially be purged by the standardsolution and its components. Assume that button FBI has been pushed toperform test number 1. A solenoid valve V1 normally blocks sample line13 and places standard line 31 in communication with process line 32.The standard base fluid S1 is drawn through line 31 by one of a seriesof pumps P driven by a motor M1. For this particular test there arethree pumps P, with one of them arranged to draw either the standard S1through line 31 or the sample through line 13. The other pumps P arearranged to draw reagents R1 and R5 from the containers for the variousstandards and reagents which can comprise any suitable liquid containers29, carried by a shelf or holder device 30.

The standard S1 is pumped through line 32 to a mixing device 33, then toa heating device 34, and finally to a dispensing outlet 35. As thestandard S1 is drawn through line 31, reagents R1 and R5 are drawnthrough lines 36 and 37 and pumped into line 32 where they are combinedwith standard S1.

Initially, the standard solution components are used to purge the lines31, 32, pumps P, the mixing and heating devices 33 and 34, and outlet35. To this end, the apparatus initially dispenses the standard solutioninto a waste drain 36 which leads to a sump 37. Then after sufiicientfluid has passed for the desired purging, waste drain 36 is shifted by asolenoid 38 to the position indicated in phantom in FIG. 8, whereuponthe final standard solution is dispensed into the cuvette 16 for thattest.

When a sufiicient quantity of standard solution has been prepared,solenoid 40 is energized to shift valve V1 to draw the sample fromextractor 3 through the line 13, and into the line 3. Simultaneouslywaste drain 36 is returned to its full line, normal position, until thesample solution is ready for dispensing into cuvette 17. The pumpscontinue to draw reagents R1 and R5 into line 32, whereby the samplesolution is mixed at 33, heated at 34, and otherwise prepared in thesame manner as the standard solution. A solenoid 41 is energized toretract its armature 42 against a spring 43 and thereby shift thedispensing nozzle carrier 44, to the right in FIG. 6, to position thedispensing nozzle outlet 35 over the cuvette 17 for that test.

Drain 36 is in waste position at all times, except when solutions arebeing dispensed into the cuvettes.

All of the foregoing is accomplished automatically, by means to bedescribed. The mixing can be accomplished by any desired mixing means,such as for example a make and break vibrator type of solenoid motor 45for shifting an armature 46 back and forth to agitate the solutionspassing through the mixing chamber 33 carried thereby. The heatingdevice can be of the fluid bath type, with a stirring device asindicated at 47 for maintaining uniform temperature throughout the bath.

The procedure is the same, for each of the various tests, except thatthe number and point of application of the reagent solutions will varyfrom test to test. This is shown in FIG. 7, wherein the broken linerepresentations indicate that other, or additional reagent containersmight be provided. While each test procedure might require only onereagent, any number of reagents can be provided and there would onlyhave to be provided a corresponding number of pumps and lines forwithdrawing each reagent through its own pump and line. Thus, in testprocedure No. 2, the standard S2 will be drawn through line 46, andreagents R2 and R4 will be drawn through lines 47 and 48, the procedurebeing the same as before except that reagent R4 will be mixed withreagent R2 prior to entry thereof into the processing line 49.

In test No. 3, standard S3 will be drawn through line 50 and one reagentR3 will be drawn through line 51 and combined with the standard inprocess line 52. For test procedure No. 4, the standard S4 is drawnthrough line 53, while the reagents R6 and R7 are drawn through lines 54and 55, and as in test No. 2, mixed together prior to delivery thereofinto process line 56-. In test No. 5 the standard S5 is drawn throughline 56, and the one reagent R8 through line 57, the two being combinedin line 58. However, it will be appreciated that this arrangement isonly illustrative of the variations which are possible.

The pumps P are ganged together to be driven by the various motorsMl-MS, as shown, and I prefer to use piston pumps having built in checkvalves so that when the pump is not being driven, it closes the line inwhich it is connected. By using each pump for only one line, the pumpsare not cross contaminated in any way, and only the one fluid passesthrough each line and pump until they are combined. By wasting theinitial discharge, all of the standard and reagent lines are initiallyclean.

The control circuit for the various solenoids and motors is illustratedin FIG. 9, from which it is seen that all of them are energized from acommon source, not shown, which could be 110 volts A.C., under controlof the main start switch '6. When this switch is closed, a light 60 isilluminated, showing that the system is on, and this light canilluminate the dial of colorimeter 22. When heater 34 is at the properbath temperature, thermostat switch '61 opens the energizing circuit tothe heater and closes an energizing circuit for light 9, indicating thatthe apparatus is ready.

Assume that test No. 1 is initiated by closing pushbutton switch PBl.This closes a circuit through a line 62, to energize a relay 63. Relay63 then closes a switch 64, completing a relay holding circuit throughlines 62 and 65, and switch 66. Relay 63 also closes a switch 67, whichcompletes an energizing circuit through lines 68, 69 and 70 to a light71 which can be contained within pushbutton FBI to illuminate the sameand thereby indicate that test procedure No. 1 has been activated.Switch 67 also prepares an energizing circuit for solenoid 40 of valveV1 and pump motor M1, under control of normally open switches 72 and 73,respectively. Switches 74 and 75 control the energization of thedispensing outlet and waste drain control solenoids 41 and 38,respectively, while switches 76 and 77 control the energization ofextractor motors 27 and 28, respectively. Solenoids 41 and 38, andmotors 27 and 28 are energized by direct current, through transformer 78and bridge rectifier 79, with a filtering condenser 80 being insertedacross the DO line.

Switches 66 and 72-77 are under control of a timer motor 81 which isenergized by a circuit including lines 68 and 83, switch 82, and lines84 and 85 and controlled by the normally open lid switch 7. Therefore,the timer motor will not start to operate, and only the relay holdingcircuit will be energized, until cover 8 is closed, to close lid switch7. Vibrator motor 45 is similarly controlled by switches 82 and 7, whichalso actuate a lock 86 to hold the cover 8 in its closed positionpending completion of the sample and standard solution processingoperations.

As clearly evident from FIG. 9, control circuits are provided for eachtest procedure, with the;respective test circuits being activated bypushbuttons PB2-PB5 under control of switch 6 and interlock switch 7 andtimer motor 81. Since they are identical with relay 63 and associatedcontrol circuits just described with reference to test No. 1, it isbelieved that detailed description and tracing of the control circuitsfor test procedures 2 through 5 would be needless repetition.

Timer motor 81 rotates a cam for controlling the various switches 66 and72-77 in predetermined sequence, and is designed so that the switches 76and 77 are closed first to energize the extractor motors. Switch 73 alsois closed at this time, completing a circuit to pump motor M1, causingthe associated pumps P to draw the standard S1 and reagents R1 and R5into process line 32. The initial standard solution is dispensed towaste. Then, switch 75 is closed, to energize waste control solenoid 38and shift waste drain 36 out of the way. After an appropriate timeinterval, switch 72 closes to energize solenoid 40. This causes the pumpP to draw sample fluid, which by now has been extracted, from theextractor bowl. Switch 74 then closes, to energize solenoid 41 and shiftthe dispensing nozzles 35 into alinement with the sample solutioncuvettes 17.

When preparation of the solutions has been completed, switch 66 opensthe relay holding circuit, deenergizing relay 63, and closes anenergizing circuit to buzzer 14 through line 88 and the normally opencontact of switch 66, line 89, switch 90 and line 91, signaling theoperator that the various solutions are ready. The operator thencompares the sample solutions with the standard solutions, in thecolorimeter which is first standarized to the respective standardsolutions. In doing this, the dial is set to a predetermined reference,for each standard solution. The dial indication for the sample solutionis then directly interpreted from the various color coded scalesprovided.

FIGS. 10 and 11 show a disposable hypodermic having a barrel terminatingat one end in a fitting 101 for a conventional needle, not shown, andhaving a single grip portion 102 at its opposite end. The bore 104 ofthe barrel is traversed by a plunger 105 having at one end a thumbbearing portion 106 and carrying a piston 107 at its opposite end.

The plunger stem is of cruciform cross section, as shown at 108, withtwo of the section flanges carrying yieldable detents 110 extendinglaterally therebeyond. The detents 110 are undercut, as shown at 112,whereby they can be compressed inwardly as the plunger stern movesinwardly along the barrel. More than one pair of detents 110 andundercuts 112 will be provided, FIG. 10 showing two pair.

In operation, the plunger 105 is withdrawn, to extract blood or whateverfluid is being tested. The operator then depresses the plunger to injectpart of the sample into a liner 104. As the first set of detents 110engages the barrel 100 they resist further inward movement, indicatingby feel alone that the necessary quantity of fluid has been ejected. Theoperator then ejects the second portion of fluid into a liner 5, withthe second set of detents resisting further inward movement, asillustrated in FIG. 10. The entire hypodermic will be made of aninexpensive plastic and offers the advantage that it can be disposableand does not require direct reading of a measuring scale by theoperator.

Accordingly, it is seen that my invention fully accomplishes itsintended objects, providing an apparatus which can be used by unskilledpersonnel to prepare solutions .and perform comparison tests andanalyses with consistent accuracy. While I have disclosed only one,illustrative embodiment, that has been done by way of illustration onlywithout throught of limitation.

Having fully disclosed and completely described my invention, and itsmode of operation, what I claim as new is.

1. Apparatus of the class described comprising, processing meansoperable to prepare a sample solution, a

housing enclosing said processing means, extractor means including areceptacle having an axis and means for rotating said receptacle aboutsaid axis, a cover movable relative to said housing between an openposition exposing said extractor means and a closed position coveringthe same, and means for withdrawing a sample fiuid from said receptacleincluding a conduit carried by said cover for movement therewith, saidconduit being arranged for communication with said processing means andhaving an intake end positioned in said receptacle along said axis whensaid cover is in said closed position.

2. Apparatus as set forth in claim 1, together with control means forsaid processing means including a normally open switch, and. meansclosing said switch when said cover is in said closed position.

3. Apparatus as set forth in claim 1, wherein said receptacle comprisesan extractor bowl, together with a disposable liner for said extractorbowl.

4. Apparatus of the class described comprising, sample supply means,standard supply means, processing means common to said standard andsample supply means and operable to prepare standard and samplesolutions for comparison testing, and means operable to place first oneof said supply means and then the other of said supply means incommunication with said processing means, whereby first one solution andthen the other solution is processed, wherein said sample supply meansincludes a receptacle for a sample to be tested, said receptacle beingsymmetrical about an axis, means for rotating said receptacle about saidaxis to extract from a sample therein, and supply line means arranged toextend into said receptacle along said axis for withdrawing therefrom.

5. Apparatus for preparing samples and standards for comparison testingcomprising sample supply means including a centrifuge extractor and afirst supply conduit arranged for communication therewith, standardsupply means including a second supply conduit separate from said firstconduit, processing means common to said standard and sample supplymeans and adapted for communication alternately with said standard andsample supply conduits, control means for said apparatus includingactivating switch means and means initially placing said commonprocessing means in communication with one of said supply conduits, saidcontrol means also including timer means automatically operable to shiftsa'id common processing means out of communication with said one supplyconduit and substantially immediately thereafter into communication withthe other of said supply conduits for processing of the sample andstandard to be compared in substantially immediate sequential relationto thereby provide substantial identity in the processing of the sampleand standard to be compared, said control means being automaticallyoperable to place said common processing means in communication withsaid second supply conduit to process a standard for each time that saidcommon processing means is placed in communication with said firstsupply conduit to process a sample, whereby a fresh standard is preparedfor each processed sample.

6. Apparatus as in claim 5, together with common reagent supply meansincluding a third supply conduit separate from said first and secondconduits, said third conduit communicating with said processing means.

7. Apparatus as in claim 6, wherein said process means includes a commonprocess conduit adopted for communication with said first and secondconduits, together with separate pumps in said process and reagentconduits, said third conduit communicating with said process conduitdown-stream of the pump therein.

8. Apparatus as set forth in claim 5, wherein said control means placesaid standard supply conduit in communication with said processing meansprior to said sample supply conduit whereby it is the standard which isprocessed first.

9. Apparatus as set forth in claim 8, wherein said control meansincludes means automatically operable to initially discharge theprocessed standard to waste.

10. Apparatus as set forth in claim 5, wherein said processing meansincludes mixing means.

11. Apparatus as set forth in claim 5, wherein said processing meansincludes heating means.

12. Apparatus as set forth in claim 5, wherein the processed sample andstandard are solutions, together with solution discharge meanscommunicating with said processing means, said control means includingmeans operable automatically to shift said discharge means from a firstposition for discharging of standard solution to a second position fordischarging of sample solution.

13. Apparatus for preparing samples and standards for comparison testingcomprising sample supply means, including a first conduit, standardsupply means including a second conduit separate from said firstconduit, processing means operable automatically to prepare standard andsample solutions for comparison testing, reagent supply means common tosaid standard and sample supply means including third conduit meansseparate from said first and second conduits communicating with saidprocessing means, and control means automatically operable to place saidfirst and second conduits in communication with said processing meansand to place said second conduit in communication with said processingmeans for each time that said first conduit is placed in communicationtherewith, thereby causing said processing means to prepare a freshstandard solution for each sample solution, wherein said processingmeans are common to said standard and sample supply means forsubstantial identity in the processing of the solutions to be compared,said control means including means alternately connecting saidprocessing means to said sample and standard supply conduits, whereinsaid supply means include a pair of centrifuge extractor bowls, andwherein said supply conduits include a first separate supply conduitfrom each of said bowls.

14. Apparatus for preparing samples and standards for comparison testingcomprising sample supply means including a centrifuge extractor and afirst conduit communicating therewith, standard supply means including asecond conduit separate from said first conduit, processing means commonto said sample and standard supply means and operable to successivelyprepare samples and standards for comparison testing, and. control meansautomatically operable to actuate said extractor and to place saidprocessing means in communication with said standard supply means toprocess a standard while the sample to be compared therewith is beingextracted, said control means including timer means automaticallyoperable to thereafter shift said processing means out of communicationwith said standard supply means and into communication with saidextractor to process the extracted sample, whereby a fresh standard isprovided for each processed sample.

15. Apparatus for preparing samples and standards for comparison testingcomprising sample supply means including a first conduit, standardsupply means including a second conduit separate from said firstconduit, processing means operable automatically to prepare standard andsample solutions for comparison testing, reagent supply means common tosaid standard and sample supply means including third conduit meansseparate from said first and second conduits communicating with saidprocessing means, and control means automatically operable to place saidfirst and second conduits in communication with said processing meansand to place said second conduit in communication with said processingmeans for each time that said first conduit is placed in communicationtherewith, thereby causing said processing means to prepare a freshstandard solution for each sample solution, wherein said processingmeans are common to said standard and sample supply means forsubstantial identity in the processing of the solutions to be compared,said control means including means alternately connecting saidprocessing means to said sample and standard supply conduits, whereinsaid sample supply means includes a centrifuge extractor, said firstconduit being arranged for communication with said extractor.

References Cited UNITED STATES PATENTS 10 3,116,118 12/1963 Whitehead eta1. 23253 3,148,146 9/1964 Asnes et al. 233-26 X 3,186,800 6/1965Strickler 23253 3,015,544 1/ 1962 Shafier et al. 23-230 OTHER{REFERENCES Fister, Harold 1.: Manual of Standardized Procedures forSpectrophotometric Chemistry, Standard Scientific Supply Corporation,New York (1951)), Introduction, pages 1 and 2, method A-10.1 to A10.3,and method A-l2.1 to A12.3

MORRIS O. WOLK, Primary Examiner.

R. E. SERWIN, Assistant Examiner.

Us. 01. X.R. 23-230, 259

1. APPARATUS OF THE CLASS DESCRIBED COMPRISING, PROCESSING MEANSOPERABLE TO PREPARE A SAMPLE SOLUTION, A HOUSING ENCLOSING SAIDPROCESSING MEANS, EXTRACTOR MEANS INCLUDING A RECEPTACLE HAVING AN AXISAND MEANS FOR ROTATING SAID RECEPTACLE ABOUT SAID AXIS, A COVER MOVABLERELATIVE TO SAID HOUSING BETWEEN AN OPEN POSITION EXPOSING SAIDEXTRACTOR MEANS AND A CLOSED POSITION COVERING THE SAME, AND MEANS, FORWITHDRAWING A SAMPLE FLUID FROM SAID RECEPTACLE INCLUDING A CONDUITCARRIED BY SAID COVER FOR MOVEMENT THEREWITH, SAID CONDUIT BEINGARRANGED FOR COMMUNICATION WITH SAID PROCESSING MEANS AND HAVING ANINTAKE END POSITIONED IN SAID RECEPTACLE ALONG SAID AXIS WHEN SAID COVERIS IN SAID CLOSED POSITION.